Various characteristics of applications determine different requirements of mobility management schemes. Realtime applications especially lay strict limitation on handoff latency and latency stretch. This limitation is exacerbated when system robust, scalability and load balancing are required simultaneously. In this paper, we present a peer-to-peer based mobility support scheme that keeps advantages of P2P on robustness and scalability as well as optimizes handoff latency and latency stretch. Moreover, a proxy handoff mechanism is proposed to ensure the optimal performance in movement. Analysis and experiments based on OpenDHT reveal proxy handoff works effectively and handoff latency about 50 ms with latency stretch value 1.14 can be achieved.